This invention relates to anti-G protection and high altitude protection devices of pilots operating high performance aircraft and spacecraft.
During high speed maneuvers in modern-day fighter aircraft, pilots are exposed to acceleration levels that can exceed human tolerance. Devices have been developed to protect pilots primarily from the +G.sub.Z (head-to-foot or "eyeballs down") acceleration experienced during rapid turns, during a pull up from a dive or during other combat maneuvers. These techniques include the use of anti-G suits, Positive Pressure Breathing (PPB) and muscular straining. Although increasing pilot G-Tolerance, these measures do not fully protect pilots from G levels produced by both modern and future high performance aircraft.
To provide higher levels of G protection, other devices have been developed. For example, U.S. Pat. No. 4,923,147 entitled "Head Support/Spine Offloading Ejection Seat Insert" assigned to Rockwell International Corporation, and U.S. Pat. No. 4,925,133 entitled "Hydraulic Buoyancy Force Suit" also assigned to Rockwell International Corporation disclose devices for protecting pilots from high levels of +G.sub.Z acceleration.
Although neither of these devices has yet been flown in an aircraft, tests have shown the value of both a buoyancy suit and a head support/spine offloading device for pilot acceleration protection.
The Integrated Crew Protection System (ICPS) disclosed herein includes a buoyancy suit and thus the +G.sub.Z protection capabilities of this type of G-protection device. In addition, as will be described below with the use of a pressurized helmet whose pressure can be regulated by acceleration levels, an ICPS also provides protection from -G.sub.Z (foot-to-head or "eyeballs up") acceleration, a feature not found in the '147 patent, the '133 patent or in other G-protection devices such as PPB or G-suit systems. Furthermore, in other G-protection systems such as the "Combination Anti-G and Pressure Suit" suit disclosed by Row in U.S. Pat. No. 5,007,893, -G.sub.Z acceleration protection is not provided. Thus the ICPS disclosed herein provides high levels of G protection for the complete range of G.sub.Z acceleration; i.e., acceleration in both the + and - directions along an axis representing G.sub.Z forces.
In addition to acceleration protection requirements, pilots of modern high performance aircraft can fly at altitudes that are intolerable to human pilots and thus have an altitude protection need. Protection from the low atmospheric pressures at high altitude is typically provided by a pressurized cockpit. During emergencies including battle damage and cockpit pressure system failures, the cockpit can depressurize leaving an unprotected pilot exposed to potentially fatal low atmospheric pressures. In these depressurization emergencies, a pressurized flight suit can save a pilot's life. In addition, a pressurized flight suit used during routine operations and not just during emergencies can result in a decreased pressurization requirement for a cockpit. A decreased pressure requirement results in decreased cockpit weight with a concomitant increase in aircraft performance.
Pilots of spacecraft are also faced with the need for pressurized flight suits to provide emergency protection and to reduce cabin pressurization requirements. Because of the higher altitudes, the effect of cabin depressurization can be more severe in spacecraft than in high performance aircraft.
With the pressure transfer component of the ICPS disclosed herein, high altitude protection is provided to altitudes encountered by pilots of spacecraft, not just high performance aircraft. Thus, in addition to +G.sub.Z and -G.sub.Z acceleration protection capabilities, the ICPS provides altitude protection thereby protecting pilots of high performance aircraft and spacecraft from two of the greatest hazards encountered during flight, namely acceleration and altitude. This dual protection feature of the ICPS is not provided by other G-protection or high altitude protection equipment.
In addition to acceleration and high altitude hazards, pilots of modern, high performance aircraft are also faced with thermal, biological, chemical and radiation hazards.
Thermal hazards occur during normal and emergency operations in excessively hot or cold environments. If the thermal environment raises or lowers body temperature more than 1.degree. or 2.degree. C., the ability of a pilot to perform normal flight tasks can be impaired. If the changes in core temperature are too extreme, ethality can result. Thus, thermal protection must be provided to ensure pilot comfort, unimpaired task performance and survival. The ICPS with a thermal management system, provides this protection capability. As will be disclosed below, the temperature of the fluid flowing through the ICPS hydraulic force buoyancy can be easily regulated to warm or cool a pilot wearing the suit. Because the suit covers most of the body, the heating and cooling capability of the ICPS is better than would be provided by currently-available cooling and heating vests that circulate water through a vest surrounding just the torso.
As will be shown below, the thermal regulating capability that is part of the ICPS is also useful for chemical, biological and radiation (CBR) protection. During combat, the possibility of attacks from chemical, biological and nuclear weapons necessitates the use of protective equipment including garments made of CBR protective materials. These garments are usually uncomfortable and hot. The thermal management system of the ICPS could be used to maintain a comfortable body temperature for subjects wearing CBR garments over the ICPS hydraulic force buoyancy suit. The hydraulic force buoyancy suit itself can be made of CBR protective materials thereby eliminating the need for separate CBR protective garments. Similarly, the pressurized helmet and breathing mask that are part of the ICPS could also provide CBR protection eliminating the need for separate CBR hood and mask ensembles. With CBR filters and other modifications, the ICPS could be a complete, self-contained CBR protection system that would also provide protection acceleration and high altitude. The ability of a single life support system worn by a pilot to provide protection from these multiple hazards is not found in currently available G-protection, high altitude or CBR protection equipment.
Furthermore, during ejections over cold ocean waters, pilots can be exposed to water temperatures that will cause hypothermia and death unless protective measures are employed. As will be disclosed below, the ICPS includes an Emergency Thermal Management System (ETMS) located in the pilot's survival pack. The ETMS circulates warm water through the hydraulic force buoyancy suit component thereby keeping a pilot warm while exposed to cold, potentially lethal water; With this ETMS, a pilot's life could be preserved until rescue could be affected. This emergency warming feature of the ICPS is not available in survival kits used in modern, high performance aircraft and thus represents a significant improvement over current survival equipment.